3D Printing Technology in Craniofacial Surgery and Salivary Gland Regeneration

Abstract

Patient-specific three-dimensional (3D)-printed phantoms and surgical guides are being utilized more often nowadays to assist diagnosis and treatment planning for surgery, which are tailored to individual’s unique needs. 3D printing surgical guides made of temporary materials can be fabricated to fit the surface of the hard or soft tissue organs by 3D modeling of the surgical interface. To date, the value of 3D printing for surgical planning as a guidance tool has been proven in various hard tissue surgical applications, such as craniofacial and maxillofacial surgery, spine surgery, cardiovascular surgery, neurosurgery, pelvic surgery, and visceral surgery. Craniofacial plastic surgery is one of the medical fields that pioneered the use of the 3D printing concept. Rapid prototyping technology was introduced to medicine in the 1990s via CAD-CAM (computer-aided design, computer-aided manufacturing). The medical models or bio-models based on the 3D printing technique represent 1:1 scale reproductions of the human anatomical region of interest that can be obtained via 3D medical imaging. The procedure for the fabrication of medical models comprises multiple steps: (1) acquisition of high-quality volumetric 3D image data of the anatomical structure to be modeled, (2) 3D image processing to extract the region of interest from the surrounding tissues, (3) mathematical surface modeling of the anatomic surfaces, (4) formatting of data for rapid prototyping, (5) model building, and (6) quality assurance of the model and its dimensional accuracy. Furthermore, tissue engineers also experience the advent of a new 3D printing era. The tissue engineering triad comprises cells, scaffolds, and growth factors. Recently, 3D technology has become sufficiently evolved to enable printing of living cells. Although many challenging issues remain to be resolved for such complex structures, heart, kidney, and skin regenerations are being investigated using 3D bioprinting technology. A potential candidate for a clinical success resides in the regeneration of the major salivary glands, which consist of various cells encapsulated by a connective tissue membrane.